In the past, a broadcasting has been a one directional one-to-plural service, which unilaterally provides simple contents, such as images and sounds, to unspecified individuals. However, in the future, with a digitization in broadcasting and advances in communication techniques, the broadcasting will make progress in a direction that a bi-directional interactive service is activated and thus various additional high-quality services are pursued. Such various additional services are developing by many application developers, and a role of a host device, such as a set-top box and a television set, for using the various additional services is needed.
FIG. 1 is a view schematically exemplifying a related art digital broadcasting system.
Referring to FIG. 1, the related art digital broadcasting system includes an application server 10, a broadcasting network 20, and host devices 30 and 40.
The application server 10 stores applications for effectively providing a variety of services, such as images, sounds and additional services, to user when a broadcasting station (not illustrated) provides such a variety of services. The applications stored in the application server 10 are delivered to the host devices 30 and 40 through the broadcasting network 20, and are executed by the host devices 30 and 40.
Each of the host devices 30 and 40 stores an application required in carrying out an operation of the host devices 30 and 40 in a fabrication thereof. This application is called a native application. The host devices 30 and 40 not only execute the native applications, but also execute the various downloaded applications provided from the broadcasting station.
FIG. 2 is a diagram exemplifying a software module structure of each of the host devices, which receives a digital broadcasting.
Referring to FIG. 2, a first application, a second application, and a third application, which are applications provided from the broadcasting station, are stored in the application server 10. The first, the second and the third applications belong to one of an Advanced Common Application Platform (ACAP). an Open Cable Application Platform (OCAP) layer and a Multimedia Home Platform (MHP) layer. As examples of such applications, there are an Electronic Program Guide (EPG) application, a monitor application, etc.
An execution engine layer is a layer, which provides an environment capable of executing the native application and the applications stored in the application server 10.
A native middleware layer provides an application program interface (API) for executing the native application and the applications provided from the broadcasting station, and adjusts hardware through a hardware abstraction layer (HAL).
The HAL provides an API, so that the native middleware can control the hardware. The hardware layer is physical hardware components of the host device 30 or 40.
The host device 30 or 40 based on the software module structure constructed as described above often simultaneously executes the applications downloaded and provided from the broadcasting station with the native application. In this case, with the execution of the native application, the applications provided from the broadcasting station can change set items. At this time, if the changed items do not exist in a menu, a user can see that the host device 30 or 40 malfunctions, and thus make muddle of using the host device 30 or 40.